Reuters Health • The Doctor's Channel Daily Newscast

NEW YORK (Reuters Health) – A transdermal sumatriptan formulation, NP101, in development for acute treatment of migraine, remains effective during a year of successive uses, according to a report in Headache online February 21.

“Because its use does not entail oral or intranasal administration and because it bypasses the need for gastrointestinal absorption,” the authors comment, “the NP101 patch may be the delivery route of choice for patients with gastrointestinal signs and symptoms including nausea, vomiting, and gastric stasis.”

Further, they continue, “Because it does not expose patients to variable or excessively high sumatriptan concentrations, the NP101 patch may be the delivery route of choice for patients among whom triptan-associated adverse events are a concern.”

For the current open-label study, 183 migraine patients who had completed a randomized double-blind trial of NP101 were invited to use the product to treat migraine episodes for up to 12 months. During that time, the participants applied a total of 2089 patches.

Dr. Timothy R. Smith, with St. John’s Mercy Health Care in St. Louis, Missouri, and colleagues report that for all patch treatments over the study period, the rate of freedom from migraine pain at 2 hours after patch activation was 23.8% and relief of pain at 2 hours was 58.2%, with no evidence of waning efficacy over the 12-month period.

Patch-site reactions were cited by 45% of patients, the report indicates. Patients assessed the site as having minimal redness at the time of patch removal in 38.2% of uses, and in 65.4% of instances after 24 hours.

The incidence of triptan-associated adverse events was 1.6%. A total of 25 patients (13.7%) discontinued the study because of adverse events, 23 of them due to application-site conditions, Dr. Smith and colleagues report.

“Considered in aggregate, the pharmacokinetic and clinical data on the NP101 patch suggest that it could constitute a useful and unique formulation for the migraine patient,” they conclude.